In November 1981, he was elected to the New York State Senate, to fill the vacancy caused by the resignation of Raymond F. Gallagher, and took his seat during a special session on December 3, 1981.

[citation needed] Stachowski chaired the Commerce, Economic Development and Small Business Committee.

Stachowski also sat on the Public Authorities Control Board and the Legislative Commission on the Development of Rural Resources.

He was also a member of the Upstate Caucus On December 2, 2009, Stachowski was one of eight Democratic state senators to vote against legislation which would legalize same-sex marriage in New York.

In 2010, he ran for re-nomination, but was defeated in the Democratic primary by Erie County Legislator Tim Kennedy.